Dame Maggie Smith is set to star in the next series of Downton Abbey, according to reports.

TVLine said that the veteran actress - who has been a huge success as the acerbic Dowager Countess - will return to the next instalment of the period drama despite doubts about whether she would continue in the role.

It said that executive producer Gareth Neame confirmed to TVLine on Sunday at HBO's post-Golden Globes bash that she would be back in the fourth series.

Previously, show creator Julian Fellowes has said that he didn't know whether Dame Maggie was back.

"With Maggie, you never know," he has said. "Other [actors] sign on for the next series and they sign for this and they sign for that, but she doesn't.

"She stays her own person. But as far as I'm concerned, I hope she stays with the show until Downton falls down."